If you have found OER to adapt or remix, you should first check to see if there are any built-in authoring tools available from the repository where you found the OER. Below are tutorials of authoring tools in various OER repositories.

If the OER were 1) originally composed by Open Author in OER Common, and 2) have been given use licenses that allow for their editing and remixing, you may use the "remix this resource" option to copy and edit an Open Author resource.